Oven or Grill Burner

ABSTRACT

The invention relates to an oven or grill burner composed of a flat body delimiting an inner chamber and having fastening protrusions, wherein fastening members are composed of at least a tab made of one piece with a flat body wall or walls. In one embodiment, the burner of the present invention includes mountings for fastening a thermocouple and/or igniter and/or a venturi tube that supplies an air and gas mixture, all included as integral members of the burner. The burner of the present invention is shaped such to increase the even distribution of the air/gas mixture to outlet holes and further includes such constructive characteristics that provide for a reduction in the thickness of the metal sheet used for making the burner without compromising burner strength.

FIELD OF THE INVENTION

The present invention relates to an oven or grill burner. Moreparticularly, the present invention relates to a burner that can be usedeither for an oven or a grill and that includes a flat box bodydelimiting an inner chamber and fastening protrusions.

BACKGROUND OF THE INVENTION

Burners are known that belong to the so called flat type. These burnerscan be composed of two half shells and have the advantageouscharacteristic of including an integrated pilot burner, which is made ofone piece by bending the peripheral edges when the two half shells arejoined together. Therefore, any drawback associated to properpositioning is obviated. The main gas outlet holes and the holes forsupplying gas to the pilot burner are obtained by perforation of one ofthe two half shells. In another type of flat burner, each half shell hasa corrugated edge opposite to that of its respective opposite half shelland the gas/air mixture outlet holes are generated by coupling thoseedges. Although in this second type the perforation step is avoided, theholes still have a rather large size, which is further subjected tochanges in the heating step, and sealing problems may occur between thetwo half shells.

Flat burners typically have advantages that cannot be found in tubularburners, including that all connections, and particularly those for thethermocouple and the igniter, are prearranged in an optimized manner,and there is no need to position them. Also, unlike tubular burners,flat burners may have inner walls for modulating gas distribution amongthe various holes, and the lack of these walls might cause unevennessproblems, especially at low flame levels. Obviously, flat burners do nothave require and end-side closing member.

SUMMARY OF THE INVENTION

It is an aim of the present invention to provide a flat burner that canbe used either for an oven or a grill and that has improvements over theprior art intended to rationalize and make its manufacturing faster by[[,]] limiting and making assembly steps easier, above all by limitingoperations for fastening additional members like connections fasteningthe burner, thermocouples and igniters, and also by limiting operationsfor proper positioning.

It is another aim of the present invention to improve a burner of theabove type such to limit the total size in favor of the size of theactive part actually generating the flame.

It is also an aim of the present invention to improve the distributionof gas and air mixture inside the burner, in order to obtain a more evendistribution of the flame.

It is a further aim of the present invention to limit material waste andto allow the use of thinner metal sheets, which are also easier tohandle, without reducing the strength of the burner.

The invention reaches the above aims by providing a burner of the abovetype wherein at least fastening members are composed of at least a tabmade of one piece with flat body wall or walls.

Advantageously, the fastening tab is provided in a position coincidingwith at least a part of two opposite walls of the flat body.

Moreover, the fastening tab is provided coincident with a throughaperture made in the burner body.

According to a preferred embodiment, the fastening tab is providedcoinciding with a through aperture made in the burner body and it ispositioned inside the footprint of the burner.

Said fastening tab has an inclined portion spacing an ending fasteningportion from a burner wall, which inclined portion is substantiallyparallel to said burner wall and/or to the median plane of the burnerand/or to a fastening wall of the burner.

According to a further advantageous feature, the burner has a fuel andcomburent mixture inlet end, which end is made like a venturi tube andit is integrated as one piece in the burner body.

Advantageously, the burner is composed of two half shells separatedaccording to a plane substantially parallel to the upper and/or lowerwall of the burner, the two half shells being tightly secured one to theother by mechanically bending and pressing perimetral continuous flangesalong outer perimetral edges of the two half shells and along perimetraledges of the aperture coinciding with the fastening tab.

According to a further advantageous feature that can be provided evenindividually with respect to above described features, the inventionprovides an oven or grill burner composed of a flat body delimiting aninner chamber and having a reflecting shield that can be secured to oneof the two upper or lower walls of said flat body, the flat body beingprovided with a plurality of through apertures tightly passing the upperwall and the lower wall, the shield being provided with a central partshaped in a way corresponding to the shape of the upper and/or lowerwall and being provided with fastening tabs each coinciding with acorresponding through aperture, which tabs have such a length to projectoutwardly beyond the wall of the side opposite to the one adhering tothe central part of the reflecting shield, forming a fastening end thatcan be bent against said wall.

Said through apertures are provided at an intermediate area of recessescontacting the upper wall with the lower wall, the upper wall and thelower wall of the box flat body being tightly connected along edgesdelimiting said through apertures.

These contacting areas also form spacing members stiffening larger wallsof the burner, limiting the thickness of the metal sheet withoutcompromising stability and strength of the burner.

According to a further feature of the invention that can be providedindividually and/or in combination with one or more of the abovedescribed features, an oven or grill burner is composed of a flat bodydelimiting an inner chamber and having at least an igniter and/or aflame detecting thermocouple secured to said flat box body by one ormore mountings. These mountings for the igniter and/or the flamedetecting thermocouple are made of one piece with the burner body.

Further characteristics and improvements are taught in the dependentclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention and the advantages derivedtherefrom will be more apparent from the following detailed descriptionand from the annexed drawings, in which:

FIG. 1 is a first perspective view of a burner according to the presentinvention.

FIG. 2 is a second perspective view of the burner according to FIG. 1.

FIG. 3 is a further perspective view of the burner according topreceding figures but seen at the side opposite to the one of thepreceding figures.

FIG. 4 is a plan view of the burner at the upper side thereof.

FIG. 5 is a plan view at the lower side of the burner.

FIG. 6 is a view similar to FIG. 5 with the reflecting shield omitted.

FIG. 7 is a perspective view similar to FIG. 2 with the reflectingshield omitted.

FIG. 8 is a side view of the burner according to FIGS. 1 to 5.

FIG. 9 is a front view of the burner according to FIGS. 1 to 5 at thehead side opposite to the fuel/comburent mixture inlet side.

FIG. 10 is a front view of the burner according to FIGS. 1 to 5 at thefuel/comburent mixture inlet end side.

FIG. 11 is a perspective view of the burner sectioned along a medianlongitudinal plane perpendicular to upper and lower walls thereof.

FIG. 12 is a cross-section perspective view of the burner along atransverse plane perpendicular to the upper and lower walls thereof andpassing through apertures fitting fastening tabs of the reflectingshield.

FIG. 13 is a cross-section view of the burner according to a planeperpendicular to the upper and lower wall thereof, intersecting sidearms supporting the flame detecting thermocouple and the igniter.

FIG. 14 is a front cross-section view of the burner along a planeperpendicular to the upper and lower wall and coinciding with a pair ofthrough apertures for engaging fastening tabs of the reflecting shield,said shield being omitted.

FIG. 15 is a cross-section view of the burner similar to FIG. 14 andshowing said reflecting shield engaging tabs in through apertures andimmediately before bending projecting ends thereof against the burnerwall opposite to the wall, to which said reflecting shield is coupled.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The preferred embodiment of a burner according to the present inventionis composed of two half shells mechanically tightly connected togetherby the mutual bending and pressing of flanges.

It should be understood that the present description of the preferredembodiment is not limitative of the features of a burner according tothe present invention, which can be also be manufactured by othertechniques.

With reference to the figures, the preferred embodiment of a burneraccording to the present invention includes a first upper half shell anda second lower half shell indicated by 1 and 2 respectively. In thisregard, it shall be noted that the words upper and lower are used hereinin relation to a burner fitted inside the oven on the bottom wall orimmediately beneath the top wall thereof (grill). The two half shells 1,2 are elongated and respectively have an upper face 101 and a lower face102 and peripheral outer edges that can be mechanically and tightlyconnected to form a flat, box body which also has an elongated butsubstantially flat shape, and integrates, even in the exterior genericaspect, the typical characteristics of tubular and flat burners. Twocorresponding ends 201, 202 of the upper half shell 1 and of the lowerhalf shell 2 respectively are conformed in such a manner that, when thetwo half shells 1, 2 are joined together, they automatically form aflame arc forming head. The opposite corresponding ends 301, 302 of theshells 1, 2 are truncated and are conformed in such a manner as to forma venturi tube, so that said head end is intended to form the inlet forsupplying fuel and mixing it with comburent that is air in this case.The venturi tube extends beyond said head end of the burner and includesan end housing the fuel supplying nozzle (not shown in detail), which isprovided substantially at one or two combustion air inlet apertures. Thejunction plane between the two half shells 1, 2 is substantiallyparallel both to the bottom and/or the underside and/or the top of theoven and to the outer faces 101, 102 of the two half shells 1, 2, thelatter being therefore parallel. Accordingly, the separator plane issubstantially oriented in the direction of the fuel/comburent mixtureinlet and parallel to the two larger walls of the box flat body of theburner, that is, the walls defined as the upper and lower wallsindicated by 101 and 102.

The two half shells 1, 2 are tightly joined together by bendingcontinuous peripheral flanges that are subsequently riveted or drawn inorder to form a channel, whose outer side wall is opposite to the sidewall of the half shell 1 and includes a row of aligned holes 501 forsupplying the gas/air mixture to the channel, so to provide the pilotburner. Therefore, the pilot burner is made of one piece with the burnerbody, whereby there is no need to provide a separate part to be attachedto the tubular body, with all problems associated thereto.

The pilot burner and the row of holes 501 have a substantially U-shapedextension, whose arched portion extends along the flame arc forming headand whose stems end substantially at the truncated ends 301, 302 of thetwo half shells, more particularly at a certain distance from saidgas/air mixture inlet ends of the two half shells, with the endingportion on the gas and air mixture inlet end intended to form theintegrated venturi tube that will be described in greater detail below.Each side wall of the lower half shell 2 has an additional row of holes601 with a larger diameter, which are also provided at the flame arcforming head area and form the main gas/air mixture outlet holes.

The two half shells are shaped at the air/gas mixture inlet end area insuch a way to form the venturi tube wherein the gas and air mixture isproduced. Therefore, in this embodiment the half shells of the venturitube are made of one piece as axial extensions of the half shells 1, 2which form the box burner body, whereby, in the assembled condition, theventuri tube indicated by 5 is coaxial to the box burner body. Thetubular body of the venturi tube, composed of the extensions of the twohalf shells 1, 2, has a substantially funnel-like shape, tapering in adirection opposite to the gas/air mixture inflow, and extends beyond thecorresponding end of the burner with an end 105 supporting the gassupplying nozzle (not shown in details), which has a pair of primarycombustion air intake apertures 205. The venturi tube further has atubular sleeve (not shown), which can slide axially along the venturitube from a position in which it substantially completely closes saidintake apertures 205, to a position in which it substantially completelyopens them, thereby providing adjustment of the stoichiometric gas/airratio. Said sleeve has a screw for axially locking it in the properposition.

According to a further feature illustrated in the figures, a half shell1 has an outer peripheral flange 401 intended to form the outer, sidewall of the channel, which forms the pilot supplying gas/air mixtureacting for spreading the flame triggering the ignition, which isgenerated by an igniter 16, whose end producing the spark is provided atthe initial area of said channel on one side of the burner and in theend area thereof associated to the gas/air mixture inlet. The flange 401extends without interruptions about the outer burner perimeter from saidinitial end at the igniter 16 to a point which is diametrically oppositeon the other side of the burner passing along the head end opposite tothe gas/air mixture inlet, and at which final end there is provided thesensible point of the flame detecting thermocouple 15. The flange 401cooperates with a flange of the half shell 2 connected thereto byriveting and bending such flange(s) to form a tight closing.

In the end area opposite to the gas and air mixture inlet area and at acertain distance from said end, the burner has a tab 3 for fastening theburner to a surface. The fastening tab 3 is made of one piece with thebox burner body and [[it]] is provided at an aperture 4 of the boxburner body passing through it. Such aperture 4 is configured to easilyreach the fastening tab 3, in order to tighten it by a screw or the likecooperating with a hole 103 in said fastening tab 3.

The fastening tab 3 has an initial section 203 oriented transverse tothe plane of the corresponding burner wall (FIG. 8) and [[it]] ends witha fastening section 303 oriented substantially parallel to the burnerwall 101 and/or to the separator plane between the two half shells 1, 2.It shall be noted that the fastening tab overlaps the plane surface ofthe burner and [[it]] extends by its fastening section 303 at a certaindistance from the burner wall, to which it is overlapped. In the shownarrangement, wherein the burner is composed of two half shells 1, 2, thefastening tab 3 is composed of two shaped tongues that are obtained fromthe material of the aperture 4 of each of the two half shellsrespectively. The two tongues 701, 702 are pressed together and arecorrespondingly shaped to form the fastening tab, moreover perimetraledges of said tongues 701, 702 have perimetral flanges that tightlyclose the perimetral edges of the tongue by bending one upon the otherand by pressing and/or by drawing. Moreover, said flanges are providedalso along edges delimiting apertures in the wall of the two half shells1, 2 forming the through aperture 4 coinciding with said fastening tab,and by means of which the two half shells are tightly joined togetheralong said edge delimiting said through aperture 4.

According to a further feature of the present embodiment, when the twotongues 701, 702 are joined together, the fastening tab 3 achieves a Ushape that aids in stiffening it. Moreover, flanges bent and pressedtogether along edges aid in stiffening the burner structure, since theygenerate a sort of peripheral rib or tabs.

Edges delimiting the through aperture 4 coinciding with the fasteningtab 3 also generate a line abutting the two half shells and acting likea spacing member strengthening the flat box body of the burner in theintermediate area of its plan extension.

From the figures, still another advantageous feature of the burner ofthe present invention is clear. The half shell [[1]] 2 is shaped such tohave a central depression at the outer side thereof corresponding to aninner projection in the direction of the opposite half shell 1. Thecentral depression extends such to leave a perimetral band like aswelling extending without interruption along the longitudinal sides andalong the head end of the burner box body opposite to the gas and airmixture inlet end, forming a U-shaped perimetral chamber supplying gas.At the head end associated to the gas/air mixture inlet and to theventuri tube 5, said perimetral chamber distributing the gas/air mixtureindicated by 602 ends at a certain distance from said head end,projecting also beyond the final end of the venturi tube 5 on the sideinside the box burner body, so that the venturi tube enters to such anextent by its final gas/air mixture outlet end between ending sectionsof said U-shaped perimetral chamber 602.

The rows of holes 501 and 601 are arranged substantially along the outerwall of the half shell [[1]] 2 in the part thereof externally delimitingthe U-shaped chamber 602 supplying the gas/air mixture.

A narrowed area is formed in the inner space of the box burner body atthe central recess/projection of the half shell [[1]] 2, since thecorresponding wall of the half shell 1 does not follow the shape of saidrecess/projection of the half shell 2 except for a central shapecomposed of a central swelling of said half shell 1 provided in the wall101 substantially coinciding with the outer recess and inner projectionof the half shell 2 which has a depth that is smaller than the one ofsaid outer recess and inner projection of the half shell 2. Therefore,as shall be noted in the section views, the stems of the U-shapedperimetral chamber 602 communicate one with the other by an intermediatenarrowing chamber that helps in balancing and making even the gas/airmixture pressure inside said U-shaped chamber 602. The venturi tube 5provided coaxial to the central median axis of the burner particularlyleads [[at]] to said narrowing chamber at a certain distance from thehead end thereof on the side faced towards the gas/air mixture inlet andin a central position of the burner. Opposite to the gas/air mixtureoutlet end from the venturi tube 5, in the central narrowing chamber andat a certain distance therefrom, there is provided the transverse edgeof the through aperture 4 coinciding with the fastening tab, thusforming a transverse deviation wall for the gas/air mixture flow towardsthe two opposite longitudinal stems of the perimetral U-shaped chamberfor supplying the gas/air mixture. Even this feature helps in improvingthe even spreading of gas/air mixture flow inside the burner and alongthe outlet holes intended to form the flame, in order to obtain an evenflame the entire extension of the burner, and particularly through thelongitudinal sides and through the flame arc forming head opposite tothe gas/air mixture inlet end.

Still according to a further feature of the present embodiment, alongthe peripheral edges of the venturi tube 5, the two opposite walls 1 and2 are suitably shaped to form said venturi tube, i.e. the two halfshells thereof are in contact one with the other, in order to avoidgas/air mixture flow to escape sideways, while in the ending portion ofthe venturi tube entering inside the burner area corresponding to thecentral narrowing chamber T, the venturi tube is open sideways.Therefore, such ending portion is made like a spout, and side aperturesalong opposite side edges provide for the gas/air mixture to passtowards the ending portions of the longitudinal stems of the perimetralU-shaped chamber 602.

It shall be noted that the burner has substantially the same transverseextension in the ending portion extending along the venturi tube 5 andbeyond the end of the narrowing chamber T and that sideways of theventuri tube the two walls 101 and 102 are pressed one against the otherin order to make stiffening side tabs 11.

Since the burner has a quite large plant shape, in order to avoid thelarge burner walls to be deformed, i.e. the upper and lower walls 101and 102, there are provided spacing members 8 among them helping instrengthening the box body structure. Said spacers are advantageouslycomposed of recesses of walls 101 and 102 or only one of these that havea limited extension with respect to the total surface of said walls andthat form mutual contacting areas inside the box body. The amount anddistribution as well as the extension of these contacting areas orcontacting islands 8 is determined by the plant size of the burner, thatis, width and length, and [[it]] is selected such not to compromise thefunction of the central narrowing chamber indicated by T in sectionviews.

Advantageously, said contacting areas are provided coinciding withthrough holes 9 for fastening a reflecting shield or parabola 10. Whenthe burner is composed of two separate half shells 1 and 2 as in theshown example, the edges of said holes 9 are tightly closed according tothe already previously described technique consisting in bending flangesalong edges delimiting the holes and bending such flanges one upon theother. The parabola or reflecting shield 10 has a central area 110contacting one of the largest walls 101 or 102 of the box burner body atsaid holes 9 and has fastening tabs 210, each fitting in a correspondinghole 9 and projecting beyond the opposite wall of the burner with afastening end bend against said wall 101, thus causing the couplingbetween the parabola 10 and the burner. As can be clearly seen in thefigures, the central part of the parabola is coupled preferably to theburner wall having the central recess and perimetral swelling formingthe perimetral U-shaped chamber 602, said central part of the parabola10 being shaped complementary to said wall 102. Such arrangementproduces a shape fit which enables an operator to immediately, easilyand quickly position the parabola, and in addition it strengthens itsfastening in position to the burner. Advantageously, the central part ofthe parabola intended to be coupled to the burner wall 102 has also anaperture 410 coinciding with the through aperture 4 of the box burnerbody and associated to the fastening tab 3.

On each one of the two opposite sides and in an intermediate area of theventuri tube 5, the burner further includes mountings 14 for supportingin a predetermined position a flame detecting thermocouple 15 and anigniter 16 of the burner. Mountings 14 are made as one piece with theburner and are composed of arm-like projections of the stiffening tabs11 sideways of the intermediate portion of the venturi tube 5. Eachmounting 14 ends with a pair of transverse tabs 114 wherein a hole 214is provided, which holes are coaxial one with respect to the otheraccording to an axis having a direction inclined towards the centralaxis of the burner and towards the row of main gas/air mixture outletholes 601. The igniter 16 and the thermocouple 15 are designed to beintroduced axially to length in each of the coaxial holes 214. Positionlocking means, for example an elastic clip 17, are provided for axiallysecuring the thermocouple 15 and the igniter 16. Mountings 14 have aposition and arrangement such that the thermocouple 15 and igniter 16automatically have the proper arrangement with respect to the burner,while when assembling the thermocouple 15 and the igniter 16 only theaxial position has to be adjusted, that is the distance at whichthermocouple 15 and igniter 16 ends from the burner in order toperfectly operate. By means of this arrangement, it is easier toassemble the burner.

As it can be seen in the figures, the two arms composing the mountings14 are provided with stiffening means. In the shown embodiment, whereinthe burner is composed of two half shells, mountings 14 are composed ofextensions of both of the half shells intended to overlap one with theother and are joined together by pressing and by drawing and/or bendingflanges along perimetral edges of said extensions. Moreover, extensionsof half shells 1, 2 forming mountings 14 are shaped such to form mutualspacing areas, thus forming stiffenings as shown in the figures by 1.

As regards the construction of the burner according to the presentinvention, the embodiment shown, in which the burner is composed of onlytwo half shells mechanically and tightly joined together by commontechniques for mechanically tightly joining metal half shells, isparticularly advantageous even if some or all construction advantages ofthe burner described hereinabove can be also had with burners made bydifferent manufacturing techniques.

Each half shell is obtained by cutting and molding a sheet metal blank.In particular, the fastening tab is obtained as one piece by cutting thematerial intended to be removed, in order to make apertures forming thethrough aperture 4 of the burner coinciding therewith. In thissituation, the cutting is made only along two longitudinal edges of theaperture and along only one of the transverse edges. The two half shellsmanufactured as described above are made such to have coinciding tabs inthe area of one aperture, which are intended to be overlapped one withthe other so to form the through aperture 4 and the fastening tab 3 ofthe burner, as well as coinciding half shells of the venturi tubeintended to form a venturi tube member 5, and coinciding side extensionseach one intended to form at least a mounting supporting an igniterand/or a thermocouple when they are mounted. Mutual intermediatecontacting areas include the areas intended to form spacers, where holesfor forming through holes of the burner are provided for engagingfastening means of a parabola or a reflecting shield, and the areasalong perimetral outer edges and/or along edges of holes engaging thefastening means of the parabola as well as areas along tabs forming thefastening tab of the mechanical tight connection. Moreover, in thisembodiment one of the two half shells 2 is provided with the two rows ofholes 501 and 601 and/or with the shaping for generating the perimetralU-shaped chamber distributing the gas/air mixture.

The two half shells thus formed are fastened together and/or in thisembodiment are also further partially shaped, for example, at theintermediate spacers and/or fastening tab 3 and/or supporting arms 14 ofthe igniter and/or the shaping of the U-shaped perimetral chamberdistributing the gas/air mixture and in the area of the thermocouple bydrawing and/or molding and/or bending peripheral flanges, while an outerperipheral flange of one of the two half shell is intended to form theouter side wall delimiting a channel spreading the ignition spark.

From the foregoing description, advantages of the burner of the presentinvention are clear. First, the particular shape of the box bodyprovides an optimum distribution of the gas/air mixture inside theburner, in order to have optimum performances during the ignition and togenerate an optimum and substantially even flow of the output gas/airmixture from main holes 601. Moreover, the insertion of the venturi tube5 inside the burner limits the size of the burner, keeping the size ofthe flame unchanged relative to its distribution in the longitudinaldirection of the burner. The manufacturing as one piece of the fasteningtab and/or of the mountings of the thermocouple and/or igniter mountinglimits costs and size and makes the fitting of the burner easier. Thefact that said mountings have the above described housings for theigniter and/or the thermocouple enables an automatic optimum positioningof the thermocouple and of the igniter, leaving only a degree of freedomin the axial sliding direction of these members, making the fitting ofthe burner easier.

By arranging the fastening tab in an intermediate position of the plansurface of the burner, useless projections are avoided and the amount offlames and the length of the active part are increased with respect topredetermined dimensions of the oven chamber.

The through aperture at said tab provides for two types of the burner tobe applied, one at the bottom of the oven and the other one at the topof it to act as a grill. In this event, during manufacturing thefastening tab 3 may be deformed in a way symmetrically opposite to theone shown in the figures, so to project outwardly on the burner sideopposite with respect to the direction shown in the figures. Dependingon whether an oven burner or a grill burner is manufactured, thesubstantial change is to vary the position of the fastening tab from aposition offset with respect to the median plane to a positionsymmetrically opposite with respect to said median plane of the burnerbox body.

Further characteristics such as intermediate contact areas, and theshaping of the two half shells, provide more stiffening andstrengthening to the burner structure, enabling the use of thinner metalsheets, which are easier to shape and handle, with less weight, lesscosts and less wear of manufacturing tools.

A person skilled in the art will appreciate that the invention is notlimited to the embodiments described and illustrated herein but may begreatly varied, especially as regards construction, without departingfrom the guiding principle disclosed above and claimed below.

1. An oven or grill burner comprising: a box body delimiting an innerchamber having an upper and a lower walls, and a fastening protrusioncomprising a fastening tab that extends from the box body and that ismade of one piece with one or more of the upper or lower walls of thebox body.
 2. The burner according to claim 1, wherein the fastening tabis provided in a position substantially coinciding with at least a partof two opposite walls of the box body.
 3. The burner according to claim1, wherein the fastening tab is provided coinciding with a throughaperture made in the box body.
 4. The burner according to claim 2,wherein the fastening tab is provided in a position coinciding with atlast a part of the upper and lower walls of the box body.
 5. The burneraccording to claim 2, wherein the fastening tab includes an inclinedportion extending from the box body and an ending fastening portion fextending from the inclined portion, and wherein the ending portion issubstantially parallel to the opposite walls of the box body.
 6. Theburner according to claim 3, further comprising a fuel and comburentmixture inlet end, wherein the fuel and comburent mixture inlet end isshaped as a venturi tube and is integrated as one piece with the boxbody.
 7. The burner according to claim 6, wherein the fastening tab isprovided in an area of the burner opposite to the fuel and comburentmixture inlet end.
 8. The burner according to claim 6, wherein theaperture coinciding with the fastening tab is closed along allperimetral edges.
 9. The burner according to claim 6, wherein the boxbody comprises a first and a second half shells separated along a planesubstantially parallel to the upper and/or the lower walls of the boxbody, and wherein the first and second half shells are tightly securedtogether by mechanically bending and pressing perimetral continuousflanges along outer perimetral edges of the two half shells and alongperimetral edges of the aperture.
 10. The burner according to claim 9,wherein each of the first and second half shells has an aperture whichprovides the through aperture and into which a tab extends, wherein theapertures and the tabs of the first and second half shells arecoincident, wherein the tabs in the first and second half shells aretightly secured by pressing and/or bending perimetral flanges, andwherein the pressing and/or bending provides the fastening tab of theburner.
 11. The burner according to claim 9, wherein the outerperimetral flange of the first half shell provides an outer side and abase wall of a perimetral channel that extends without interruptionalong the longitudinal sides of the burner and also along a head end ofthe burner opposite to the fuel/comburent mixture inlet end, and whereinthe second half shell has a first row of fuel/comburent mixture outletholes provided along a perimetral band of said second half shell, andwherein the perimetral band delimits the perimetral channel on an innerside.
 12. The burner according to claim 11, wherein the first row ofholes extends along the perimetral channel inclusive of the head end ofthe burner opposite to the fuel/comburent mixture inlet end.
 13. Theburner according to claim 11, wherein a second row of fuel/comburentmixture outlet holes supplies a flame.
 14. The burner according to claim13, wherein the second row of fuel/comburent mixture outlet holes isprovided along a side wall of the second half shell beside the first rowof holes and is positioned between the first row and the lower wall. 15.The burner according to claim 13, wherein the holes of the first rowhave a diameter smaller than the holes of the second row.
 16. The burneraccording to claim 11, wherein at the fuel/comburent mixture inlet endthe first and the second half shells are shaped such to each form a halfof the venturi tube according to a diametral plane of said venturi tube,and wherein side edges of the two halves of the venturi tube are shapedto provide a tight contact one against the other.
 17. The burneraccording to claim 11, wherein a reflecting shield member is fastenableto the upper or the lower wall of the box body, wherein the reflectingshield has a central wall abutting and fastenable to the upper or thelower wall of the burner, and wherein an aperture is provided in thereflecting shield coinciding with the aperture provided in the burnerbody for the fastening tab.
 18. The burner according to claim 11,wherein the box body of the burner is shaped such to provide aperimetral U-shaped chamber extending for a predetermined length of thelongitudinal sides of the box body and along the head end, wherein theperimetral U-shaped chamber delimits an intermediate chamber for flowcommunication between longitudinal stems of the perimetral U-shapedchamber, and wherein the intermediate chamber has an inner height lowerthan an inner height of the perimetral U-shaped chamber.
 19. The burneraccording to claim 18, wherein the venturi tube extends inside the boxbody between the longitudinal stems of the perimetral U-shaped chamber.20. The burner according to claim 11, wherein one of the upper or lowerwall of the burner is substantially flat while the opposite wall has acentral depression surrounded by a perimetral swelling along thelongitudinal sides and along the head end, wherein the upper and lowerwalls extend towards the end of the box body corresponding to the fueland carburent inlet end and each comprises a central swelling having anessentially semi-conical shape to provide a longitudinal half of theventuri tube.
 21. The burner according to claim 9, wherein the first andthe second half shells are manufactured by shaping and cutting a metalsheet blank.
 22. An oven or grill burner comprising: a box bodydelimiting an inner chamber; and having an upper and a lower walls; anda reflecting shield fastenable to the upper or the lower wall of the boxbody, wherein the box body is provided with a plurality of throughopenings passing through the upper and the lower walls, wherein thereflecting shield is provided with a central portion shapedcorrespondingly to a shape of the upper and/or lower walls and isfurther provided with fastening tabs each coinciding with one of thethrough openings, and wherein the fastening extensions have such alength to project outwardly beyond the side of the box body opposite tothe reflecting shield, thereby forming a fastening end bendable againstthe box body.
 23. The burner according to claim 22, wherein the throughopenings are provided at recesses contacting the upper wall with thelower wall, and wherein the upper wall and the lower wall of the boxbody are tightly connected along edges delimiting said through openings.24. The burner according to claim 23, wherein the edges delimiting thethrough openings in the upper wall and in the lower wall of the box bodyare provided with flanges for tight connection by bending and bypressing.
 25. The burner according to claim 23, wherein the recessescontacting the upper wall with the lower wall are configured to formspacers between said two walls.
 26. The burner according to claim 23,further comprising a fastening protrusion that includes a fastening tabmade of one piece with one or more of the upper or lower wall of the boxbody.
 27. The burner according to claim 26, wherein the central part ofthe reflecting shield is shaped to substantially mate a correspondingportion of the upper or lower wall of the burner.
 28. The burneraccording to claim 27, wherein the upper or lower wall includes acentral depression, and wherein the reflecting shield in a positioncoinciding with said depression has a correspondingly shaped projectionintended to engage in said depression by a shape fit.
 29. An oven orgrill burner comprising: a box body delimiting an inner chamber; and oneor more of an igniter or a flame detecting thermocouple coupled to saidbox body by one or more mountings, wherein said one or more mountingsare made of one piece with the box body.
 30. The burner according toclaim 29, wherein said one or more mountings are composed of an arm-likeextension projecting outwardly beyond a side edge of the box body atleast at a side thereof, wherein the one or more mountings areconfigured for removably fastening the igniter and/or the thermocouple,and wherein the thermocouple and/or the igniter are supported at alimited intermediate portion of their lengths.
 31. The burner accordingto claim 29, wherein the one or more mountings are oriented such toretain the igniter and/or the thermocouple in a proper operatingposition with respect to the burner.
 32. The burner according to claim29, wherein the igniter and/or the thermocouple are adjustable axiallyafter coupling with the one or more mountings.
 33. The burner accordingto claim 29, wherein said one or more mountings comprise two supportingarms each branching out from a side edge of the box body, wherein one ofthe supporting arm is coupled to the igniter and the other supportingarm is coupled to the flame detecting thermocouple, and wherein the twoarms are made of one piece with the box body.
 34. The burner accordingto claim 33, wherein the two supporting arms are provided at an end ofthe box body corresponding to a fuel/comburent mixture inlet end. 35.The burner according to claim 29, wherein the box body comprises anupper and a lower walls, wherein a reflecting shield is fastenable tothe upper or the lower wall of the box body, wherein the box body isprovided with a plurality of through openings passing through the upperand the lower walls, wherein the reflecting shield is provided with acentral portion shaped correspondingly to a shape of the upper and/orlower walls and is further provided with fastening tabs each coincidingwith one of the through openings, and wherein the fastening extensionshave such a length to project outwardly beyond the side of the box bodyopposite to the reflecting shield, thereby forming a fastening endbendable against the box body.
 36. The burner according to claim 29,wherein the box body comprises an upper wall and a lower walls, andwherein a fastening protrusion comprises a fastening tab that extendsfrom the box body and that is made of one piece with one or more of theupper or lower walls of the box body.
 37. An oven or grill burnercomprising: a box body delimiting an inner chamber and having an upperand a lower walls, wherein the upper and the lower walls are configuredto form therebetween a peripheral U-shaped chamber distributing a gasand air mixture along longitudinal sides of the box body and furtheralong a head side opposite to a gas and air mixture inlet end, andwherein the peripheral U-shaped chamber surrounds an intermediatenarrowing chamber having a height smaller than a height of theperipheral U-shaped chamber.
 38. The burner according to claim 37,wherein a venturi tube is disposed at the gas and air mixture inlet endand is integral therewith, wherein the venturi tube is closed for aninitial portion situated towards the narrowing chamber, and wherein theventuri tube is in flow communication with the narrowing chamber that isdisposed centrally and is in flow communication with longitudinal stemsof the peripheral U-shaped chamber.
 39. The burner according to claim38, wherein the narrowing chamber comprises transverse spacing membersconnecting the upper and the lower walls.
 40. The burner according toclaim 37, wherein a fastening protrusion comprising a fastening tabextends from the box body and is made of one piece with one or more ofthe upper or lower walls of the box body, wherein the fastening tabextends over a through aperture made in the box body, wherein areflecting shield is fastenable to the upper or the lower wall of thebox body, wherein the box body is provided with a plurality of throughopenings passing through the upper and the lower walls, wherein thereflecting shield is provided with a central portion shapedcorrespondingly to a shape of the upper and/or lower walls and isfurther provided with fastening extensions each coinciding with one ofthe through openings, wherein the fastening extensions have such alength to project outwardly beyond the side of the box body opposite tothe reflecting shield, thereby forming a fastening end bendable againstthe box body, wherein one or more of an igniter or a flame detectingthermocouple is coupled to the box body by one or more mountings, andwherein the one or more mountings are made of one piece with the boxbody.
 41. The burner according to claim 40, wherein a perimetral edge ofthe through aperture is provided at a certain distance from the venturitube and deviates sideways the flow of the gas and air mixture.
 42. Theburner according to claim 38, wherein the venturi tube extends for acertain length inside the narrowing chamber and is in flow communicationwith the narrowing chamber through side apertures.